With the advent of more robust electronic systems, advancements of electronic devices are becoming more prevalent. Electronic devices can provide a variety of functions including, for example, telephonic, audio/video, and gaming functions. Handheld electronic devices can include mobile stations such as cellular telephones, smart telephones, portable gaming systems, personal computers, portable MP3 players, electronic writing or typing tablets, handheld messaging devices, and portable computers.
Some electronic devices include switch panels such as keyboards and keypads. As the available functions of electronic devices continue to increase, the functionality of the switch panels also needs to increase. Because electronic devices often have limited space for switch panels such as keyboard and keypads, the size, tactile feedback, audible feedback, and life of the switch panel can be compromised to fit the switch panel on the electronic device. In smaller electronic devices, some switch panels require a very light force and very small deflection to actuate the individual keys of the switch panel. Without any type of feedback, operators can have difficulty sensing the switch closures, and thus can have difficulty in entering input using the switch panel. To address this, some switch panels have included dome switches that provide tactile feedback and audible feedback when the keys of the switch panel are actuated.
Typical dome switch panels include a circuit board panel having conductive traces separated by a conductive gap, where the conductive traces are arranged in a keyboard or a keypad array. The conductive traces correspond to each of the keys of the keyboard or keypad array. A flexible dome is provided above each of the conductive traces. When a key of the switch panel is depressed, the flexible dome is compressed towards the circuit board panel and closes the conductive trace, thereby closing the switch to enter input to the electronic device. When pressure or force is removed from the key, the flexible dome returns to its original shape, provides a gap between the conductive traces, and opens the switch. The flexibility and deflection of the dome can provide tactile feedback and audible feedback to indicate a switch has been closed, which also indicates input has been entered to the electronic device. In some dome switch panels, adhesive layers and composite structures can be incorporated with the dome switches to hermetically seal the dome switches to prevent dust and moisture from dirtying the switch and circuit board. The additional layers and structures can increase the rigidity of the dome switches and the key, which can affect tactile and audible feedback provided to the user. The less feedback given to the user to indicate successful switch closure and input entry, the more difficulty and frustration the user can have in actuating the switch panel.